Benzochrysene derivative and organic electroluminescence device using the same

ABSTRACT

A fused aromatic ring derivative shown by the following formula (1): 
                         
wherein R a  and R b  are independently a hydrogen atom or a substituent, m and n are independently an integer of 1 to 13, and when m and n are two or more, R a s and R b s may be independently the same or different, and L 1  is a single bond or a substituted or unsubstituted divalent linking group, provided that the fused aromatic ring derivative shown by the formula (1) does not have an anthracene ring.

The invention relates to a novel fused aromatic ring derivative(benzochrysene derivative) which is useful as a material for an organicelectroluminescence device, and an organic electroluminescence deviceusing the same.

An organic electroluminescence device (hereinafter the term“electroluminescence” is often abbreviated as “EL”) is a self-emissiondevice utilizing the principle that an emitting material emits light bythe recombination energy of holes injected from an anode and electronsinjected from a cathode when an electric field is impressed.

An organic EL device has made a remarkable progress. In addition, sincean organic EL device has characteristics such as low voltage driving,high luminance, variety in emission wavelength, high response andcapability of fabricating a thin and lightweight emitting device, itsapplication to a wide range of fields is expected.

Emission materials used in an organic EL device have conventionally beenstudied actively since they influence largely the color of light emittedby a device or on emission life.

As the emission material, a chelate complex such astris(8-quinolinolato)aluminum complex, a coumarin derivative, atetraphenylbutadiene derivative, a bisstyrylarylene derivative and anoxadiazole derivative are known. By using such emission materials,emission in a visible range from blue to red can be obtained.

Use of a phosphorescent compound as an emission material for utilizingtriplet energy for emission has been studied. For example, it is knownthat an organic EL device using an iridium complex as an emissionmaterial exhibits a high luminous efficiency.

An organic EL device using polyphenylene vinylene (PPV) as a conjugatedpolymer is known. In this device, PPV is applied and formed into asingle film and this device is confirmed to emit light.

Patent Document 1 discloses an organic EL device using a layercontaining 9,10-di-(2-naphthyl)anthracene derivative as an organiclayer.

Patent Document 1: U.S. Pat. No. 5,935,721

An object of the invention is to provide an organic material which issuitable for use as a material of an organic EL device.

DISCLOSURE OF THE INVENTION

The inventor noticed a benzochrysene derivative as a material for anorganic EL device and made intensive studies. As a result, the inventorhas found that a benzochrysene derivative having a specific structure iseffective for prolonging the lifetime, increasing the efficiency andlowering the voltage of an organic EL device. The invention has beenmade on this finding.

According to the invention, the following fused aromatic ring derivativeor the like can be provided.

-   1. A fused aromatic ring derivative shown by the following formula    (1):

wherein R_(a) and R_(b) are independently a hydrogen atom or asubstituent, m and n are independently an integer of 1 to 13, and when mand n are two or more, R_(a)s and R_(b)s may be independently the sameor different, and L₁ is a single bond or a substituted or unsubstituteddivalent linking group, provided that the fused aromatic ring derivativeshown by the formula (1) does not have an anthracene ring.

-   2. The fused aromatic ring derivative according to 1 shown by the    following formula (2):

wherein R_(a) and R_(b) are independently a hydrogen atom or asubstituent, m and n are independently an integer of 1 to 13, and when mand n are two or more, R_(a)s and R_(b)s may be independently the sameor different, and L₂ is a single bond or a substituted or unsubstituteddivalent linking group, provided that the fused aromatic ring derivativeshown in the formula (2) does not have an anthracene ring.

-   3. The fused aromatic ring derivative according to 1 or 2, wherein    L₁ or L₂ is a substituted or unsubstituted arylene group having 6 to    50 carbon atoms that form a ring (hereinafter abbreviated as the    “ring carbon atoms”).-   4. A material for an organic electroluminescence device comprising    the fused aromatic ring derivative according to any one of 1 to 3.-   5. The material for an organic electroluminescence device according    to 4, which is an emitting material.-   6. An organic electroluminescence device comprising:

an anode, a cathode, and

one or more organic thin film layers comprising an emitting laterbetween the anode and the cathode,

wherein at least one of the organic thin film layers comprises thecompound according to any one of 1 to 3.

-   7. The organic electroluminescence device according to 6, wherein    the emitting layer comprises the fused aromatic ring derivative.-   8. The organic electroluminescence device according to 7, wherein    the emitting layer comprises the fused aromatic ring derivative as a    host material.-   9. The organic electroluminescence device according to any one of 6    to 8, wherein the emitting layer further comprises at least one of a    fluorescent dopant and a phosphorescent dopant.-   10. The organic electroluminescence device according to 9, wherein    the fluorescent dopent is an arylamine compound.-   11. The organic electroluminescence device according to 9, wherein    the fluorescent dopant is a styrylamine compound.-   12. The organic electroluminescence device according to 9, wherein    the phosophorescent dopant is a metal complex compound.

According to the invention, a fused aromatic ring derivative suitablefor use as a material for an organic EL device can be obtained. Anorganic EL device using the fused aromatic ring derivative of theinvention has a long life and a high efficiency and is capable of beingdriven at a low voltage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view of an organic EL deviceaccording to one embodiment of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

The fused aromatic ring derivative of the invention will be describedbelow in detail.

The fused aromatic ring derivative of the invention is a compound shownby the following formula (1):

wherein R_(a) and R_(b) are independently a hydrogen atom or asubstituent, m and n are independently an integer of 1 to 13, and when mand n are two or more, R_(a)s and R_(b)s may be the same or different,and L₁ is a single bond or a substituted or unsubstituted divalentlinking group, provided that the fused aromatic ring derivative shown bythe formula (1) does not have an anthracene ring.

In the formula (1), L₁ may be bonded to any of the 14 bonding positionsof the benzochrysene ring.

Similarly, R_(a) and R_(b) may be bonded to any of the 13 bondingpositions except for the bonding position of L₁.

Examples of the substituent shown by R_(a) and R_(b) include an alkylgroup (one having preferably 1 to 20, more preferably 1 to 12 andparticularly preferably 1 to 8 carbon atoms, the specific examples ofwhich include methyl, ethyl, isopropyl, t-butyl, n-octyl, n-decyl,n-hexadecyl, cyclopropyl, cyclopentyl and cyclohexyl), an alkenyl group(one having preferably 2 to 20, more preferably 2 to 12 and particularlypreferably 2 to 8 carbon atoms, the specific examples of which includevinyl, allyl, 2-butenyl and 3-pentenyl), an alkynyl group (one havingpreferably 2 to 20, more preferably 2 to 12 and particularly preferably2 to 8 carbon atoms, the specific examples of which include propynyl and3-pentynyl), and a substituted or unsubstituted aryl group (one havingpreferably 6 to 20 and particularly preferably 6 to 14 carbon atoms, thespecific examples of which include phenyl, naphthyl, naphthylphenyl,phenylnaphthyl, naphthylnaphthyl, phenanthryl, fluorenyl, provided thatan anthracene ring is not contained). Examples of the substituent forthe aryl group include an aryl group (one having preferably 6 to 20 andparticularly preferably 6 to 14 carbon atoms, the specific examplesinclude phenyl, naphthyl and phenanthryl, provided that an anthracenering is not contained), a heterocyclic group (one having preferably 1 to30 and more preferably 1 to 12 carbon atom, the specific examples ofwhich include imidazolyl, pyridyl, quinolyl, furyl, thienyl, piperidyl,morpholino, benzooxazolyl, benzoimidazolyl, benzothiazolyl, carbazolyl,benzofuranyl, dibenzofuranyl, benzothiophenyl and dibenzothiophenyl), asubstituted or unsubstituted amino group (one having preferably 0 to 20,more preferably 0 to 12 and particularly preferably 0 to 6 carbon atoms,the specific examples of which include amino, methylamino,dimethylamino, diethylamino, diphenylamino and dibenzylamino), an alkoxygroup (one having preferably 1 to 20, more preferably 1 to 12 andparticularly preferably 1 to 8 carbon atoms, the specific examples ofwhich include methoxy, ethoxy and buthoxy), an aryloxy group (one havingpreferably 6 to 20, more preferably 6 to 16 and particularly preferably6 to 12 carbon atoms, the specific examples of which include phenyloxyand 2-naphthyloxy), an acyl group (one having preferably 1 to 20, morepreferably 1 to 16 and particularly preferably 1 to 12 carbon atoms, thespecific examples of which include acetyl, benzoyl, formyl andpivaloyl), an alkoxycarbonyl group (one having preferably 2 to 20, morepreferably 2 to 16 and particularly preferably 2 to 12 carbon atoms, thespecific examples of which include methoxycarbonyl and ethoxycarbonyl),an aryloxycarbonyl group (one having preferably 7 to 20, more preferably7 to 16 and particularly preferably 7 to 10 carbon atoms, the specificexamples of which include phenyloxycarbonyl), an acyloxy group (onehaving preferably 2 to 20, more preferably 2 to 16 and particularlypreferably 2 to 10 carbon atoms, the specific examples of which includeacetoxy and benzoyloxy), an acylamino group (one having preferably 2 to20, more preferably 2 to 16 and particularly preferably 2 to 10 carbonatoms, the specific examples of which include acetylamino andbenzoylamino), an alkoxycarbonylamino group (one having preferably 2 to20, more preferably 2 to 16 and particularly preferably 2 to 12 carbonatoms, the specific examples of which include methoxycarbonylamino), anaryloxycarbonylamino group (one having preferably 7 to 20, morepreferably 7 to 16 and particularly preferably 7 to 12 carbon atoms, thespecific examples of which include phenylcarbonylamino), a substitutedor unsubstituted sulfonylamino group (one having preferably 1 to 20,more preferably 1 to 16 and particularly preferably 1 to 12 carbonatoms, the specific examples of which include methanesulfonylamino andbenzenesulfonylamino), a substituted or unsubstituted sulfamoyl group(one having preferably 0 to 20, more preferably 0 to 16 and particularlypreferably 0 to 12 carbon atoms, the specific examples of which includesulfamoyl, methylsulfamoyl, dimethylsulfamoyl and phenylsulfamoyl), asubstituted or unsubstituted carbamoyl group (one having preferably 1 to20, more preferably 1 to 16 and particularly preferably 1 to 12 carbonatoms, the specific examples of which include carbamoyl,methylcarbamoyl, diethylcarbamoyl and phenylcarbamoyl), an alkylthiogroup (one having preferably 1 to 20, more preferably 1 to 16 andparticularly preferably 1 to 12 carbon atoms, the specific examples ofwhich include methylthio and ethylthio), an arylthio group (one havingpreferably 6 to 20, more preferably 6 to 16 and particularly preferably6 to 12 carbon atoms, the specific examples of which includephenylthio), a substituted or unsubstituted sulfonyl group (one havingpreferably 1 to 20, more preferably 1 to 16 and particularly preferably1 to 12 carbon atoms, the specific examples of which include mesyl andtosyl), a substituted or unsubstituted sulfinyl group (one havingpreferably 1 to 20, more preferably 1 to 16 and particularly preferably1 to 12 carbon atoms, the specific examples of which includemethanesulfinyl and benezenesulfinyl), a substituted or unsubstitutedureido group (one having preferably 1 to 20, more preferably 1 to 16 andparticularly preferably 1 to 12 carbon atoms, the specific examplesinclude ureido, methylureido and phenylureido), a substituted orunsubstituted phosphoric amide group (one having preferably 1 to 20,more preferably 1 to 16 and particularly preferably 1 to 12 carbonatoms, the specific examples of which include diethylphosphoric amideand phenylphosphoric amide), a hydroxy group, a mercapto group, ahalogen atom (for example, a fluorine atom, a chlorine atom, a bromineatom and an iodine atom), a cyano group, a sulfo group, a carboxylgroup, a nitro group, a hydroxamic acid group, a sulfino group, ahydrazino group, an imino group, a heterocyclic group (one havingpreferably 1 to 30 and more preferably 1 to 12 carbon atoms andcontaining, as the hetero atom, a nitrogen atom, an oxygen atom and asulfur atom, for example, the specific examples of which includeimidazolyl, pyridyl, quinolyl, furyl, thienyl, piperidyl, morpholino,benzoxazolyl, benzimidazoyl, benzothiazolyl, carbazolyl, benzofuranyl,dibenzofuranyl, benzothiophenyl and dibenzothiophenyl), and a silylgroup (one having preferably 3 to 40, more preferably 3 to 30 andparticularly preferably 3 to 24 carbon atoms, the specific examples ofwhich include trimethylsilyl and triphenylsilyl). These substituents maybe further substituted. If there are two or more substituents, thesesubstituents may be the same or different.

Of these, an alkyl group, an alkenyl group, an aryl group, an arylaminogroup, a carbazolyl group, a carbazolylaryl group, a dibenzofuranyl arylgroup and a dibenzothiophenyl aryl group are preferable.

As the substituted or unsubstituted divalent linking group shown by L₁,for example, a substituted or unsubstituted alkylene group, asubstituted or unsubstituted arylene group having 6 to 50 ring carbonatoms and a substituted or unsubstituted heterocyclic group having 5 to50 atoms that form a ring (hereinafter referred to as the “ring atoms”)can be given.

As examples of the substituted or unsubstituted alkylene group, adivalent group obtained by removing one hydrogen atom from the followingalkyl groups having 1 to 20 carbon atoms can be given:

Methyl, ethyl, isopropyl, t-butyl, n-octyl, n-decyl, n-hexadecyl,cyclopropyl, cyclopentyl, cyclohexyl.

As the substituent of these, the above-mentioned alkyl group, or thearyl group or the heterocyclic group given later can be given, forexample.

As examples of the substituted or unsubstituted arylene group having 6to 50 ring carbon atoms, a divalent group obtained by removing onehydrogen atom from the following aryl groups can be given:

A phenyl group, 1-naphthyl group, 2-naphthyl group, 1-phenanthryl group,2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group,9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group,9-naphthacenyl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group,2-biphenylyl group, 3-biphenylyl group, 4-biphenylyl group,p-terphenyl-4-yl group, p-terphenyl-3-yl group, p-terphenyl-2-yl group,m-terphenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-2-yl group,o-tolyl group, m-tolyl group, p-tolyl group, p-t-butylphenyl group,p-(2-phenylpropyl)phenyl group, 3-methyl-2-naphthyl group,4-methyl-1-naphthyl group, 4′-methylbiphenylyl group,4″-t-butyl-p-terphenyl-4-yl group, triphenylenyl group, benzanthranylgroup, 1-chrysenyl group, 2-chrysenyl group, 6-chrysenyl group,phenyl-1-naphthyl group, phenyl-2-naphthyl group, naphthyl-1-naphthylgroup, naphthyl-2-naphthyl group.

As the substituent of these, the above-mentioned alkyl group, or thearyl group or the heterocyclic group given later can be given, forexample.

As examples of the substituted or substituted heterocyclic group having5 to 50 ring atoms, a divalent group obtained by removing one hydrogenatom from the following monovalent heterocyclic ring groups can begiven:

Imidazolyl, pyridyl, quinolyl, furyl, thienyl, piperidyl, morpholino,benzooxazolyl, benzoimidazolyl, benzothiazolyl, carbazolyl,benzofuranyl, dibenzofuranyl, benzothiophenyl, dibenzothiophenyl.

As the substituent of these, the alkyl group, the aryl group or theheterocyclic group as mentioned above can be given, for example.

It may be a group obtained by combining two or more of divalent groupssuch as the arylene group, the heterocyclic group, the single bond, thealkylene group or the like as mentioned above, or a group having afluorene structure. For example, the following groups can be given.

In particular, the following divalent groups are preferable.

The fused aromatic ring derivative of the invention does not have ananthracene ring. Here, the “does not have an anthracene ring” means thatL₁ or L₂ does not have an anthracenyl group, an anthracenylene group orthe like. That is, the fused aromatic ring derivative of the inventiondoes not mean one which has an anthracene skeleton in a fused ring, suchas naphthacene and penthacene.

M and n are independently an integer of 1 to 13. In the invention, it ispreferred that all of R_(a) and R_(b) are hydrogen atoms.

In the fused aromatic ring derivative of the invention, the 10^(th)position of the following benzo[g]chrysene has a high reactivity.

Therefore, the fused aromatic ring derivative of the invention ispreferably one shown by the following formula (2), in which asubstituent is bonded to the 10^(th) position:

wherein R_(a), R_(b), m and n are as defined in the formula (1). L₂ isthe same group as L₁ in the formula (1).

The specific examples of the fused aromatic ring derivative of theinvention will be given below.

The fused aromatic ring derivative can be synthesized by a method inwhich a dihalogen compound having the above-mentioned structure L₁ isreacted with an intermediate obtained by hydroborating thebenzo[g]chrysene synthesized by referring to the following literatures.

-   [Synthesis 2001, No. 6, 841-844]-   [J. Org. Chem. 2005, 70, 3511-3517]-   [Journal of the American Chemical Society 96:14 Jul. 10, 1974,    4617-4622]

The fused aromatic ring derivative of the invention can be preferablyused as a material for an organic EL device, in particular, as theemitting material thereof.

The organic EL device of the invention comprises an anode, a cathode andone or more organic thin layers comprising an emitting layer between theanode and the cathode, and at least one of the organic thin layerscomprise the above-mentioned compound of the invention.

Representative configurations of the organic EL device of the inventioncan be given below.

-   (1) Anode/emitting layer/cathode-   (2) Anode/hole-injecting layer/emitting layer/cathode-   (3) Anode/emitting layer/electron-injecting layer/cathode-   (4) Anode/hole-injecting layer/emitting layer/electron-injecting    layer/cathode-   (5) Anode/organic semiconductor layer/emitting layer/cathode-   (6) Anode/organic semiconductor layer/electron-barrier    layer/emitting layer/cathode-   (7) Anode/organic semiconductor layer/emitting    layer/adhesion-improving layer/cathode-   (8) Anode/hole-injecting layer/hole-transporting layer/emitting    layer/electron-injecting layer/cathode-   (9) Anode/insulating layer/emitting layer/insulating layer/cathode-   (10) Anode/inorganic semiconductor layer/insulating layer/emitting    layer/insulating layer/cathode-   (11) Anode/organic semiconductor layer/insulating layer/emitting    layer/insulating layer/cathode-   (12) Anode/insulating layer/hole-injecting layer/hole-transporting    layer/emitting layer/insulating layer/cathode-   (13) Anode/insulating layer/hole-injecting layer/hole-transporting    layer/emitting layer/electron-injecting layer/cathode

The representative examples of the configuration of the organic ELdevice of the invention are, however, not limited to the above. Ofthese, the configuration (8) is preferable.

The configuration (8) is shown in FIG. 1. This organic EL devicecomprises an anode 10, a cathode 20, and a hole-injecting layer 30, ahole-transporting layer 32, an emitting layer 34 and anelectron-injecting layer 36 between the anode and the cathode. Thehole-injecting layer 30, the hole-transporting layer 32, the emittinglayer 34 and the electron-injecting layer 36 correspond to the pluralityof organic thin film layers. At least one of these organic thin filmlayers 30, 32, 34 and 36 comprises the compound of the invention.

In the organic EL device of the invention, although the compound of theinvention may be used in any of the above-mentioned organic thin filmlayers, it is preferred that the compound of the invention be used inthe emitting layer. In each of the organic thin film layers, thecompound of the invention may be used either singly or in mixture withother compounds. In the device of the invention, it is preferred thatthe emitting layer contain the compound of the invention as a hostmaterial and contain at least one of a fluorescent dopant and aphosphorescent dopant.

In the invention, it is preferred that the emitting layer consistessentially of the compound of the invention and the above-mentioneddopant.

The content of the compound of the invention in the organic thin filmlayers is preferably 30 to 100 mol %.

Each member of the organic EL device will be explained below.

The organic EL device is normally formed on a substrate. The substratesupports the organic EL device. It is preferable to use a smoothsubstrate. If light is outcoupled through the substrate, it is preferredthat the substrate be a transparent substrate with a transmission tovisible rays with a wavelength of 400 to 700 nm of 50% or more.

As such tranparent substrate, a glass plate, a synthetic resin plate orthe like are preferably used. Examples of the glass plate include platesof soda-lime glass, barium/strontium-containing glass, lead glass,aluminosilicate glass, borosilicate glass, barium borosilicate glass,quartz, or the like. Examples of the synthetic resin plates includeplates of a polycarbonate resin, an acrylic resin, a polyethyleneterephthalate resin, a polyether sulfide resin, a polysulfone resin, orthe like.

It is effective that the anode injects holes to the hole-injectinglayer, the hole-transporting layer or the emitting layer and has a workfunction of 4.5 eV or more. Specific examples of the anode materialinclude indium tin oxide (ITO), a mixture of indium oxide and zincoxide, a mixture of ITO and cerium oxide (ITCO), a mixture of themixture of indium oxide, and zinc oxide and cerium oxide (IZCO), amixture of indium oxide and cerium oxide (ICO), a mixture of zinc oxideand aluminum oxide (AZO), tin oxide (NESA), gold, silver, platinum andcopper.

The anode can be formed from these electrode materials by a vapordeposition method, a sputtering method or the like.

In the case where emission from the emitting layer is outcoupled throughthe anode, the transmittance of the anode to the emission is preferablymore than 10%. The sheet resistance of the anode is preferably severalhundred Ω/□ or less. The film thickness of the anode, which variesdepending upon the material thereof, is usually from 10 nm to 1 μm,preferably from 10 to 200 nm.

The emitting layer has the following functions.

-   (i) Injection function: function of allowing injection of holes from    the anode or hole-injecting layer and injection of electrons from    the cathode or electron-injecting layer upon application of an    electric field-   (ii) Transporting function: function of moving injected carriers    (electrons and holes) due to the force of an electric field-   (iii) Emission function: function of recombining electons and holes    to emit light

As the method of forming the emitting layer, a known method such asdeposition, spin coating, or an LB method may be applied. It ispreferable that the emitting layer be a molecular deposition film. Themolecular deposition film is a film formed by deposition of a materialcompound in a gas phase, or by solidification of a material compound inthe form of a solution or in a liquid phase. The molecular depositionfilm can be usually distinguished from a thin film (molecularaccumulation film) formed using the LB method by the difference inaggregation structure or higher order structure or the difference infunction due to the difference in structure.

The emitting layer may also be formed by dissolving a binder such as aresin and a material compound in a solvent to obtain a solution, andforming a thin film from the solution by spin coating or the like.

Specific examples of the emitting material which can be used in theemitting layer include for example, anthracene, naphthalene,phenanthrene, pyrene, tetracene, coronene, chrysene, fluorescein,perylene, phthaloperylene, naphthaloperylene, perynone, phthaloperynone,naphthaloperynone, diphenyl butadiene, tetraphenyl butadiene, coumarin,oxadiazole, aldazine, bisbenzoxazoline, bisstyryl, pyrazine,cyclopentadiene, quinoline metal complexes, aminoquinoline metalcomplexes, benzoquinoline metal complexes, imine, diphenylethylene,vinylanthracene, diaminocarbazole, pyran, thiopyran, polymethine,merocyanine, imidazole chelated oxinoid compounds, quinacridone,rubrene, and derivatives thereof, and fluorescent pigments, but are notlimited to these.

Specific examples of the host material which can be used in the emittinglayer include compounds shown by the following formulas (i) to (ix):

Asymmetrical anthracene represented by the following formula (i):

wherein Ar⁰⁰¹ is a substituted or unsubstituted fused aromatic grouphaving 10 to 50 ring carbon atoms,

Ar⁰⁰² is a substituted or unsubstituted aromatic group having 6 to 50ring carbon atoms,

X⁰⁰¹ to X⁰⁰³ are independently a substituted or unsubstituted aromaticgroup having 6 to 50 ring carbon atoms, a substituted or unsubstitutedaromatic heterocyclic group having 5 to 50 ring atoms, a substituted orunsubstituted alkyl group having 1 to 50 carbon atoms, a substituted orunsubstituted alkoxy group having 1 to 50 carbon atoms, a substituted orunsubstituted aralkyl group having 6 to 50 carbon atoms, a substitutedor unsubstituted aryloxy group having 5 to 50 ring atoms, a substitutedor unsubstituted arylthio group having 5 to 50 ring atoms, a substitutedor unsubstituted alkoxycarbonyl group having 1 to 50 carbon atoms, acarboxyl group, a halogen atom, a cyano group, a nitro group and ahydroxy group,

a, b and c are each an integer of 0 to 4.

n is an integer of 1 to 3, and when n is two or more, groups in the [ ]smay be the same or different.

Asymmetrical monoanthracene derivatives represented by the followingformula (ii):

wherein Ar⁰⁰³ and Ar⁰⁰⁴ are independently are a substituted orunsubstituted aromatic ring group having 6 to 50 ring carbon atoms,

m and n are each an integer of 1 to 4,

provided that in the case where m=n=1 and Ar⁰⁰³ and Ar⁰⁰⁴ aresymmetrically bonded to the benzene rings, Ar⁰⁰³ and Ar⁰⁰⁴ are not thesame, and in the case where m or n is an integer of 2 to 4, m isdifferent from n,

R⁰⁰¹ to R⁰¹⁰ are independently are a hydrogen atom, a substituted orunsubstituted aromatic ring group having 6 to 50 ring carbon atoms, asubstituted or unsubstituted aromatic heterocyclic group having 5 to 50ring atoms, a substituted or unsubstituted alkyl group having 1 to 50carbon atoms, a substituted or unsubstituted cycloalkyl group, asubstituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, asubstituted or unsubstituted aralkyl group having 6 to 50 carbon atoms,a substituted or unsubstituted aryloxy group having 5 to 50 ring atoms,a substituted or unsubstituted arylthio group having 5 to 50 ring atoms,a substituted or unsubstituted alkoxycarbonyl group having 1 to 50carbon atoms, a substituted or unsubstituted silyl group, a carboxylgroup, a halogen atom, a cyano group, a nitro group or a hydroxyl group.

Asymmetrical pyrene derivatives shown by the following formula (iii):

wherein Ar⁰⁰⁵ and Ar⁰⁰⁶ are independently an aromatic group having 6 to50 ring carbon atoms,

L⁰⁰¹ and L⁰⁰² are independently a substituted or unsubstituted phenylenegroup, a substituted or unsubstituted naphthalenylene group, asubstituted or unsubstituted fluolenylene group, or a substituted orunsubstituted dibenzosilolylene group,

m is an integer of 0 to 2, n is an integer of 1 to 4, s is an integer of0 to 2, and t is an integer of 0 to 4,

L⁰⁰¹ or Ar⁰⁰⁵ bonds at any one position of 1 to 5 of the pyrene, andL⁰⁰² or Ar⁰⁰⁶ bonds at any one position of 6 to 10 of the pyrene;provided that when n+t is an even number, Ar⁰⁰⁶, Ar⁰⁰⁶, L⁰⁰¹ and L⁰⁰²satisfy the following (1) and (2):

(1) Ar⁰⁰⁶≠Ar⁰⁰⁶ and/or L⁰⁰¹≠L⁰⁰² where ≠ means these substituents aregroups having different structures from each other,

(2) when Ar⁰⁰⁵=Ar⁰⁰⁶ and L⁰⁰¹=L⁰⁰²,

(2-1) m≠s and/or n≠t, or

(2-2) when m=s and n=t,

(2-2-1) when L⁰⁰¹ and L⁰⁰² or pyrene are independently bonded todifferent bonding positions of Ar⁰⁰⁵ and Ar⁰⁰⁶, or (2-2-2) when L⁰⁰¹ andL⁰⁰² or pyrene are bonded to the same position of Ar⁰⁰⁵ and Ar⁰⁰⁶, thepositions of the substitution of L⁰⁰¹ and L⁰⁰² or Ar⁰⁰⁵ and Ar⁰⁰⁶ atpyrene are neither the 1^(st) position and the 6^(th) position, nor the2^(nd) position and the 7^(th) position.

Asymmetrical anthracene shown by the following formula (iv):

wherein A⁰⁰¹ and A⁰⁰² are independently a substituted or unsubstitutedfused aromatic ring group having 10 to 20 ring carbon atoms,

Ar⁰⁰⁷ and Ar⁰⁰⁸ are independently a hydrogen atom or a substituted orunsubstituted aromatic ring group having 6 to 50 ring carbon atoms,

R⁰¹¹ to R⁰²⁰ are independently are a hydrogen atom, a substituted orunsubstituted aromatic ring group having 6 to 50 ring carbon atoms, asubstituted or unsubstituted aromatic heterocyclic group having 5 to 50ring atoms, a substituted or unsubstituted alkyl group having 1 to 50carbon atoms, a substituted or unsubstituted cycloalkyl group, asubstituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, asubstituted or unsubstituted aralkyl group having 6 to 50 carbon atoms,a substituted or unsubstituted aryloxy group having 5 to 50 ring atoms,a substituted or unsubstituted arylthio group having 5 to 50 ring atoms,a substituted or unsubstituted alkoxycarbonyl group having 1 to 50carbon atoms, a substituted or unsubstituted silyl group, a carboxylgroup, a halogen atom, a cyano group, a nitro group or a hydroxyl group,and

there may be a plurality of Ar⁰⁰⁷, Ar⁰⁰⁸, R⁰¹⁹ and R⁰²⁰, respectively,and adjacent groups thereof may form a saturated or unsaturated ringstructure,

provided that groups do not symmetrically bond to 9 and 10 positions ofthe central anthracene with respect to X-Y axis.

Anthracene derivative represented by the following formula (v):

wherein R⁰²¹ to R⁰³⁰ are independently a hydrogen atom, an alkyl group,a cycloalkyl group, a substituted or unsubstituted aryl group, an alkoxygroup, an aryloxy group, an alkylamino group, an alkenyl group, anarylamino group or a substituted or unsubstituted heterocyclic group,

a and b are independently an integer of 1 to 5, and when they are two ormore, R⁰²¹s or R⁰²²s may be the same or different, R⁰²¹s or R⁰²²s may bebonded to form a ring, R⁰²³ and R⁰²⁴, R⁰²⁵ and R⁰²⁶, R⁰²⁷ and R⁰²⁸, andR⁰²⁹ and R⁰³⁰ may be bonded to each other to form a ring, and

L⁰⁰³ is a single bond, —O—, —S—, —N(R)— (R is an alkyl group or asubstituted or unsubstituted aryl group), an alkylene group or anarylene group.

Anthracene derivative shown by the following formula (vi):

wherein R⁰³¹ to R⁰⁴⁰ are independently a hydrogen atom, an alkyl group,a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, analkylamino group, an arylamino group or a substituted or unsubstitutedheterocyclic group,

c, d, e and f are independently an integer of 1 to 5, and when they aretwo or more, R⁰³¹s, R⁰³²s, R⁰³⁶s or R⁰³⁷s may be the same or different,R⁰³¹s, R⁰³²s, R⁰³³s or R⁰³⁷s may be bonded to form a ring, and R⁰³³ andR⁰³⁴, and R⁰³⁹ and R⁰⁴⁰ may be bonded to each other to form a ring, and

L⁰⁰⁴ is a single bond, —O—, —S—, —N(R)— (R is an alkyl group or asubstituted or unsubstituted aryl group), an alkylene group or anarylene group.

Spirofluorene derivative represented by the following formula (vii):

wherein A⁰⁰⁵ to A⁰⁰⁸ are independently a substituted or unsubstitutedbiphenyl or a substituted or unsubstituted naphthyl group.Fused ring-containing compounds shown by the following formula (viii):

wherein A⁰¹¹ to A⁰¹³ represent the same divalent group as Li in theformula (1),

A⁰¹⁴ to A⁰¹⁶ represent the same substituent as R_(a) in the formula (1),and

R⁰⁴¹ to R⁰⁴³ are independently a hydrogen atom, alkyl group having 1 to6 carbon atoms, cycloalkyl group having 3 to 6 carbon atoms, alkoxylgroup having 1 to 6 carbon atoms, aryloxy group having 5 to 18 carbonatoms, aralkyloxy group having 7 to 18 carbon atoms, arylamino grouphaving 5 to 16 carbon atoms, nitro group, cyano group, ester grouphaving 1 to 6 carbon atoms, or a halogen atom, provided that at leastone of A⁰¹¹ to A⁰¹⁶ is a group having a fused aromatic ring with threeor more rings.

Fluorene compounds shown by the following formula (ix):

wherein R⁰⁵¹ and R⁰⁵² are a hydrogen atom, a substituted orunsubstituted alkyl group, a substituted or unsubstituted aralkyl group,a substituted or unsubstituted aryl group, a substituted orunsubstituted heterocyclic group, substituted amino group, cyano group,or a halogen atom,

R⁰⁵¹s or R⁰⁵²s bonded to different fluorene groups may be the same ordifferent, and R⁰⁵¹ and R⁰⁵² bonded to a single fluorene group may bethe same or different,

R⁰⁵³ and R⁰⁵⁴ are independently a hydrogen atom, a substituted orunsubstituted alkyl group, a substituted or unsubstituted aralkyl group,a substituted or unsubstituted aryl group or a substituted orunsubstituted heterocyclic group, R⁰⁵³s or R⁰⁵⁴s bonded to differentfluorene groups may be the same or different, and R⁰⁵³ and R⁰⁵⁴ bondedto a single fluorene group may be the same or different,

Ar⁰¹¹ and Ar⁰¹² are a substituted or unsubstituted fused polycyclicaromatic group with a total number of benzene rings of three or more ora fused polycyclic heterocyclic group which is bonded to the fluorenegroup through substituted or unsubstituted carbon and has a total numberof benzene rings and heterocyclic rings of three or more, provided thatAr⁰¹¹ and Ar⁰¹² may be the same or different, and

n is an integer of 1 to 10.

In the case of using a phosphorescent dopant, specific examples of thehost compounds include carbazole, triazole, oxazole, oxadiazole,imidazole, polyarylalkane, pyrazoline, pyrazolone, phenylenediamine,arylamine, amino-substituted calcone, styrylanthracene, fluorenone,hydrazone, stilbene and silazane derivatives; aromatic tertiary amine,styrylamine, aromatic dimethylidene and porphyrin compounds,anthraquinodimethane, anthrone, diphenylquinone, thiopyrandioxide,carbodiimide, fluorenylidenemethane and distyrylpyrazine derivatives;heterocyclic tetracarboxylic anhydrides such as naphthaleneperylene,phthalocyanine derivatives, metal complexes of 8-quinolinol derivatives,various metal complex polysilane compounds represented by metalcomplexes having metalphthalocyanine, benzoxazole or benzothiazole as aligand, electroconductive high molecular oligomers such aspoly(N-vinylcarbazole) derivatives, aniline copolymers, thiopheneoligomers and polythiophene, and polymer compounds such aspolythiophene, polyphenylene, polyphenylenevinylene and polyfluorenederivatives. The host compounds may be used singly or in combination oftwo or more.

Specific examples include the following compounds.

In the organic EL device of the invention, it is preferred that theemitting layer contain the emitting material of the invention as a hostand contain at least one of a phosphorescent dopant and a fluorescentdopant. An emitting layer containing these dopants may be stacked on anemitting layer containing the compound of the invention.

A phosphorescent dopant is a compound that can emit light from tripletexcitons. The dopant is not limited so long as it can emit light fromtriplet excitons, but it is preferably a metal complex containing atleast one metal selected from the group of Ir, Ru, Pd, Pt, Os and Re. Aporphyrin metal complex or an ortho-metalated metal complex ispreferable. The phosphorescent compounds can be used individually or asa combination of two or more kinds.

As a porphyrin metal complex, a porphyrin platinum complex ispreferable.

There are various ligands forming an ortho-metalated metal complex.Preferable ligands include compounds having a phenylpyridine skeleton, abipyridyl skeleton or a phenanthroline skeleton, 2-phenylpyridine,7,8-benzoquinoline, 2-(2-thienyl)pyridine, 2-(1-naphthyl)pyridine and2-phenylquinoline derivatives. These ligands may have a substituent, ifnecessary. Ligands to which fluorides, e.g. a trifluoromethyl group,being introduced as a substituent are particularly preferable as a bluedopant. As an auxiliary ligand, preferred are ligands other than theabove-mentioned ligands, such as acetylacetonate and picric acid may becontained.

Specific examples of the metal complex include the following compounds.In the invention, it is preferred that the metal complex be combinedwith a phosphorescent dopant which gives emission in a red region.However, the metal complex is not limited thereto, and can beappropriately selected by the required emission color, the deviceperformance and the host compound used.

The content of a phosphorescent dopant in an emitting layer is notlimited and can be properly selected according to purposes; for example,it is 0.1 to 70 mass %, preferably 1 to 30 mass %. When the content of aphosphorescent compound is less than 0.1 mass %, emission may be weakand the advantages thereof may not be sufficiently obtained. When thecontent exceeds 70 mass %, the phenomenon called concentration quenchingmay significantly proceed, thereby degrading the device performance.

As for the fluorescent dopant, it is preferable to select a compoundfrom amine-based compounds, aromatic compounds, chelate complexes suchas tris(8-quinolilate)aluminum complexes, coumarin derivatives,tetraphenylbutadiene derivatives, bisstyrylarylene derivatives,oxadiazole derivatives or the like, taking into consideration requiredemission colors. Of these, styrylamine compounds, styryldiaminecompounds, arylamine compounds and aryldiamine compounds are furtherpreferable. Fused polycyclic aromatic compounds which are not an aminecompound are also preferable. These fluorescent dopants may be usedsingly or in combination of two or more.

The content of a fluorescent dopant in the emitting layer is notparticularly limited and can be appropriately selected according topurposes; for example, it is 0.1 to 70 mass %, preferably 1 to 30 mass%.

As the styrylamine compound and the styryldiamine compound, those shownby the following formula (A) are preferable.

wherein Ar¹⁰¹ is a group with a valence of p corresponding to a phenylgroup, a naphthyl group, a biphenyl group, a terphenyl group, astilbenzyl group or a distyrylaryl group, Ar¹⁰² and Ar¹⁰³ areindependently an aromatic hydrocarbon group having 6 to 20 carbon atoms,Ar¹⁰¹, Ar¹⁰² and Ar¹⁰³ may be substituted, one of Ar¹⁰¹ to Ar¹⁰³ issubstituted by a styryl group, further preferably, at least one of Ar¹⁰²and Ar¹⁰³ is substituted by a styryl group, and p is an integer of 1 to4, preferably an integer of 1 to 2.

Here, as the aromatic hydrocarbon group having 6 to 20 carbon atoms, aphenyl group, a naphthyl group, an anthranyl group, a phenanthryl group,a terphenyl group or the like can be given.

As the arylamine compound and the aryldiamine compound, those shown bythe following formula (B) are preferable.

wherein A¹¹¹ is a substituted or unsubstituted aromatic group with avalence of q having 5 to 40 ring carbon atoms, Ar¹¹² and Ar¹¹³ areindependently a substituted or unsubstituted aryl group having 5 to 40ring carbon atoms, and q is an integer of 1 to 4, preferably an integerof 1 to 2.

Examples of the aryl group having 5 to 40 ring carbon atoms include aphenyl group, a naphthyl group, an anthranyl group, a phenanthryl group,a pyrenyl group, a coronenyl group, a biphenyl group, a terphenyl group,a pyrrolyl group, a furanyl group, a thiophenyl group, a benzothiophenylgroup, an oxadiazolyl group, a diphenylanthranyl group, an indolylgroup, a carbazolyl group, a pyridyl group, a benzoquinolyl group, afluoranthenyl group, an acenaphthofluoranthenyl group, a stilbene group,a perylenyl group, a chrysenyl group, a picenyl group, a triphenylenylgroup, a rubicenyl group, a benzanthracenyl group, a phenylanthranylgroup and a bisanthracenyl group. Preferred are a naphthyl group, ananthranyl group, chrysenyl group and a pyrenyl group.

As the Ar¹¹¹, the above-mentioned q-value group is preferable. WhenAr¹¹¹ is a divalent group, groups shown by the following formulas (C)and (D) are preferable. A group shown by the formula (D) is morepreferable.

(in the formula (C), r is an integer of 1 to 3)

Preferred substituents for the above-mentioned aryl group include analkyl group having 1 to 6 carbon atoms (ethyl, methyl, i-propyl,n-propyl, s-butyl, t-butyl, pentyl, hexyl, cyclopentyl, cyclohexyl, orthe like); an alkoxy group having 1 to 6 carbon atoms (ethoxy, methoxy,i-propoxy, n-propoxy, s-buthoxy, t-buthoxy, penthoxy, hexyloxy,cyclopentoxy, cyclohexyloxy, or the like); an aryl group having 5 to 40ring carbon atoms; an amino group substituted with an aryl group having5 to 40 ring carbon atoms; an ester group with an aryl group having 5 to40 ring carbon atoms; an ester group with an alkyl group having 1 to 6carbon atoms; a cyano group; a nitro group; and a halogen atom.

The emitting layer may contain hole-transporting materials,electron-transporting materials and polymer binders, if necessary.

The thickness of an emitting layer is preferably from 5 to 50 nm, morepreferably from 7 to 50 nm and most preferably from 10 to 50 nm. When itis less than 5 nm, the formation of an emitting layer and the adjustmentof chromaticity may become difficult. When it exceeds 50 nm, the drivingvoltage may increase.

The hole-transporting layer and the hole-injecting layer are layerswhich help the injection of holes into the emitting layer so as totransport holes to an emitting region, and have a large hole mobilityand normally have such a small ionization energy as 5.5 eV or less. Asthe material for the hole-injecting layer and the hole-transportinglayer, a material which transports holes to the emitting layer at alower electrical field is preferable, and the hole mobility thereof ispreferably 10⁻⁴ cm²/V·second or more when an electric field of, e.g.,10⁴ to 10⁶ V/cm is applied.

There are no particular restrictions on the material for thehole-injecting layer and the hole-transporting layer. The material canbe arbitrarily selected from materials which have been widely used as ahole-transporting material of photoconductive materials and knownmaterials used in a hole-injecting layer and a hole-transporting layerof organic EL devices.

In the hole-injecting layer and the hole-transporting layer, an aromaticamine derivative shown by the following formula can be used, forexample.

wherein Ar²¹¹ to Ar²¹³, Ar²²¹ to Ar²²³ and Ar²⁰³ to Ar²⁰⁸ areindependently a substituted or unsubstituted aromatic hydrocarbon grouphaving 6 to 50 ring carbon atoms or a substituted or unsubstitutedaromatic heterocyclic group having 5 to 50 ring atoms, a to c and p to rare independently an integer of 0 to 3, and Ar²⁰³ and Ar²⁰⁴, Ar²⁰⁵ andAr²⁰⁶, or Ar²⁰⁷ and Ar²⁰⁸ may be bonded to each other to form asaturated or unsaturated ring.

Examples of the substituted or unsubstituted aromatic ring groups having6 to 50 ring carbon atoms include a phenyl group, 1-naphthyl group,2-naphthyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group,1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group,4-phenanthryl group, 9-phenanthryl group, 1-naphthacenyl group,2-naphthacenyl group, 9-naphthacenyl group, and 1-pyrenyl group,2-pyrenyl group, 4-pyrenyl group, 2-biphenylyl group, 3-biphenylylgroup, 4-biphenylyl group, p-terphenyl-4-yl group, p-terphenyl-3-ylgroup, p-terphenyl-2-yl group, m-terphenyl-4-yl group, m-terphenyl-3-ylgroup, m-terphenyl-2-yl group, o-tolyl group, m-tolyl group, p-tolylgroup, p-t-butylphenyl group, p-(2-phenylpropyl)phenyl group,3-methyl-2-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl-1-anthrylgroup, 4′-methylbiphenylyl group, and 4″-t-butyl-p-terphenyl-4-yl group.

Examples of the substituted or unsubstituted aromatic heterocyclic grouphaving 5 to 50 ring atoms include a 1-pyrrolyl group, 2-pyrrolyl group,3-pyrrolyl group, pyrazinyl group, 2-pyridinyl group, 3-pyridinyl group,4-pyridinyl group, 1-indolyl group, 2-indolyl group, 3-indolyl group,4-indolyl group, 5-indolyl group, 6-indolyl group, 7-indolyl group,1-isoindolyl group, 2-isoindolyl group, 3-isoindolyl group, 4-isoindolylgroup, 5-isoindolyl group, 6-isoindolyl group, 7-isoindolyl group,2-furyl group, 3-furyl group, 2-benzofuranyl group, 3-benzofuranylgroup, 4-benzofuranyl group, 5-benzofuranyl group, 6-benzofuranyl group,7-benzofuranyl group, 1-isobenzofuranyl group, 3-isobenzofuranyl group,4-isobenzofuranyl group, 5-isobenzofuranyl group, 6-isobenzofuranylgroup, 7-isobenzofuranyl group, quinolyl group, 3-quinolyl group,4-quinolyl group, 5-quinolyl group, 6-quinolyl group, 7-quinolyl group,8-quinolyl group, 1-isoquinolyl group, 3-isoquinolyl group,4-isoquinolyl group, 5-isoquinolyl group, 6-isoquinolyl group,7-isoquinolyl group, 8-isoquinolyl group, 2-quinoxalinyl group,5-quinoxalinyl group, 6-quinoxalinyl group, 1-carbazolyl group,2-carbazolyl group, 3-carbazolyl group, 4-carbazolyl group, 9-carbazolylgroup, 1-phenanthridinyl group, 2-phenanthridinyl group,3-phenanthridinyl group, 4-phenanthridinyl group, 6-phenanthridinylgroup, 7-phenanthridinyl group, 8-phenanthridinyl group,9-phenanthridinyl group, 10-phenanthridinyl group, 1-acridinyl group,2-acridinyl group, 3-acridinyl group, 4-acridinyl group, 9-acridinylgroup, 1,7-phenanthrolin-2-yl group, 1,7-phenanthrolin-3-yl group,1,7-phenanthrolin-4-yl group, 1,7-phenanthrolin-5-yl group,1,7-phenanthrolin-6-yl group, 1,7-phenanthrolin-8-yl group,1,7-phenanthrolin-9-yl group, 1,7-phenanthrolin-10-yl group,1,8-phenanthrolin-2-yl group, 1,8-phenanthrolin-3-yl group,1,8-phenanthrolin-4-yl group, 1,8-phenanthrolin-5-yl group,1,8-phenanthrolin-6-yl group, 1,8-phenanthrolin-7-yl group,1,8-phenanthrolin-9-yl group, 1,8-phenanthrolin-10-yl group,1,9-phenanthrolin-2-yl group, 1,9-phenanthrolin-3-yl group,1,9-phenanthrolin-4-yl group, 1,9-phenanthrolin-5-yl group,1,9-phenanthrolin-6-yl group, 1,9-phenanthrolin-7-yl group,1,9-phenanthrolin-8-yl group, 1,9-phenanthrolin-10-yl group,1,10-phenanthrolin-2-yl group, 1,10-phenanthrolin-3-yl group,1,10-phenanthrolin-4-yl group, 1,10-phenanthrolin-5-yl group,2,9-phenanthrolin-1-yl group, 2,9-phenanthrolin-3-yl group,2,9-phenanthrolin-4-yl group, 2,9-phenanthrolin-5-yl group,2,9-phenanthrolin-6-yl group, 2,9-phenanthrolin-7-yl group,2,9-phenanthrolin-8-yl group, 2,9-phenanthrolin-10-yl group,2,8-phenanthrolin-1-yl group, 2,8-phenanthrolin-3-yl group,2,8-phenanthrolin-4-yl group, 2,8-phenanthrolin-5-yl group,2,8-phenanthrolin-6-yl group, 2,8-phenanthrolin-7-yl group,2,8-phenanthrolin-9-yl group, 2,8-phenanthrolin-10-yl group,2,7-phenanthrolin-1-yl group, 2,7-phenanthrolin-3-yl group,2,7-phenanthrolin-4-yl group, 2,7-phenanthrolin-5-yl group,2,7-phenanthrolin-6-yl group, 2,7-phenanthrolin-8-yl group,2,7-phenanthrolin-9-yl group, 2,7-phenanthrolin-10-yl group,1-phenazinyl group, 2-phenazinyl group, 1-phenothiadinyl group,2-phenothiadinyl group, 3-phenothiadinyl group, 4-phenothiadinyl group,10-phenothiadinyl group, 1-phenoxadinyl group, 2-phenoxadinyl group,3-phenoxadinyl group, 4-phenoxadinyl group, 10-phenoxadinyl group,2-oxazolyl group, 4-oxazolyl group, 5-oxazolyl group, 2-oxadiazolylgroup, 5-oxadiazolyl group, 3-furazanyl group, 2-thienyl group,3-thienyl group, 2-methylpyrrol-1-yl group, 2-methylpyrrol-3-yl group,2-methylpyrrol-4-yl group, 2-methylpyrrol-5-yl group,3-methylpyrrol-1-yl group, 3-methylpyrrol-2-yl group,3-methylpyrrol-4-yl group, 3-methylpyrrol-5-yl group,2-t-butylpyrrol-4-yl group, 3-(2-phenylpropyl)pyrrol-1-yl group,2-methyl-1-indolyl group, 4-methyl-1-indolyl group, 2-methyl-3-indolylgroup, 4-methyl-3-indolyl group, 2-t-butyl-1-indolyl group,4-t-butyl-1-indolyl group, 2-t-butyl-3-indolyl group, and4-t-butyl-3-indolyl group.

Further, the compound shown by the following formula can be used in thehole-injecting layer and the hole-transporting layer.

wherein Ar²³¹ to Ar²³⁴ are independently a substituted or unsubstitutedaromatic hydrocarbon group having 6 to 50 ring carbon atoms, or asubstituted or unsubstituted aromatic heterocyclic group having 5 to 50ring atoms, L is a linking group, which is a single bond, a substitutedor unsubstituted aromatic hydrocarbon group having 6 to 50 ring carbonatoms or a substituted or unsubstituted aromatic heterocyclic grouphaving 5 to 50 ring atoms, x is an integer of 0 to 5, and Ar²³² andAr²³³ may be bonded to each other to form a saturated or unsaturatedring.

As specific examples of the substituted or unsubstituted aromatichydrocarbon group having 6 to 50 ring carbon atoms and substituted orunsubstituted aromatic heterocyclic group having 5 to 50 ring atoms, thesame as those exemplified above for the aromatic amine derivative can begiven.

As specific examples of the material for the hole-injecting layer andthe hole-transporting layer, a triazole derivative, an oxadiazolederivative, an imidazole derivative, a polyarylalkane derivative, apyrazoline derivative, a pyrazolone derivative, a phenylenediaminederivative, an arylamine derivative, an amino-substituted chalkonederivative, an oxazole derivative, a styrylanthracene derivative, afluorenone derivative, a hydrazone derivative, a stilbene derivative, asilazane derivative, an aniline-based copolymer, and conductivehigh-molecular oligomers (in particular, a thiophene oligomer) can begiven.

As the material for the hole-injecting layer and the hole-transportinglayer, although the above-mentioned materials can be used, it ispreferable to use a porphyrin compound, an aromatic tertiary aminecompound and a styrylamine compound. It is particularly preferable touse an aromatic tertiary amine compound.

It is preferable to use a compound having two fused aromatic rings inthe molecule thereof, for example,4,4′-bis(N-(1-naphthyl)-N-phenylamino)biphenyl (abbreviated by NPD,hereinafter), and4,4′,4″-tris(N-(3-methylphenyl)-N-phenylamino)triphenylamine(abbreviated by MTDATA, hereinafter) wherein three triphenylamine unitsare linked in a star-burst form.

In addition to the above, a nitrogen-containing heterocyclic derivativeshown by the following formula can also be used.

wherein R²⁰¹ to R²⁰⁶ are independently a substituted or unsubstitutedalkyl group, a substituted or unsubstituted aryl group, a substituted orunsubstituted aralkyl group, a substituted or unsubstituted heterocyclicgroup, and R²⁰¹ and R²⁰², R²⁰³ and R²⁰⁴, R²⁰⁵ and R²⁰⁶, R²⁰¹ and R²⁰⁶,R²⁰² and R²⁰³, or R²⁰⁴ and R²⁰⁵ may form a fused ring.

Further, the following compound can also be used.

wherein R²¹¹ to R²¹⁶ are substituents; preferably they are independentlyan electron-attracting group such as a cyano group, a nitro group, asulfonyl group, a carbonyl group, a trifluoromethyl group and a halogen.

Further, an inorganic compound such as p-type Si and p-type SiC can alsobe used as a material for the hole-injecting layer and thehole-transporting layer.

The hole-injecting layer and the hole-transporting layer can be formedfrom the above-mentioned compounds by a known method such as vaporvacuum deposition, spin coating, casting or LB technique. The filmthickness of the hole-injecting layer and the hole-transporting layer isnot particularly limited, and is usually from 5 nm to 5 μm. Thehole-injecting layer and the hole-transporting layer may be a singlelayer made of one or two or more of the above-mentioned materials, ormay be of a structure in which hole-injecting layers andhole-transporting layers made of different compounds are stacked.

The organic semiconductor layer is a layer for helping the injection ofholes or electrons into the emitting layer, and is preferably a layerhaving an electric conductivity of 10⁻¹⁰ S/cm or more. As the materialof such an organic semiconductor layer, electroconductive oligomers suchas thiophene-containing oligomers or arylamine-containing oligomers andelectroconductive dendrimers such as arylamine-containing dendrimers maybe used.

The electron-injecting layer and the electron-transporting layer arelayers which assist injection of electrons into the emitting layer andtransport electrons to the emitting region, and exhibit a high electronmobility. The adhesion-improving layer is a kind of theelectron-injecting layer which is made of a material exhibitingparticularly good adhesion to the cathode.

The thickness of the electron-transporting layer is arbitrarily selectedin the range of 5 nm to 5 μm. When the electron-transporting layer has athick thickness, it is preferable that the electron mobility be 10⁻⁵cm²/Vs or more at an applied electric field of 10⁴ to 10⁶ V/cm in orderto prevent an increase in voltage.

The material used in the electron-injecting layer and theelectron-transporting layer is preferably a metal complex of8-hydroxyquinoline or a derivative thereof, or an oxadiazole derivative.Specific examples of the metal complex of 8-hydroxyquinoline orderivative thereof include metal chelate oxynoid compounds containing achelate of oxine (generally, 8-quinolinol or 8-hydroxyquinoline), e.g.tris(8-quinolinolato)aluminum.

As examples of the oxadiazole derivative, an electron-transportingcompound shown by the following formula can be given.

wherein Ar³⁰¹, Ar³⁰², Ar³⁰³, Ar³⁰⁵, Ar³⁰⁶ and Ar³⁰⁹ are independently asubstituted or unsubstituted aryl group, and Ar³⁰⁴, Ar³⁰⁷ and Ar³⁰⁸ areindependently a substituted or unsubstituted arylene group.

As examples of the aryl group, a phenyl group, a biphenyl group, ananthranyl group, a perylenyl group, and a pyrenyl group can be given. Asexamples of the arylene group, a phenylene group, a naphthylene group, abiphenylene group, an anthranylene group, a perylenylene group, apyrenylene group, and the like can be given. As the substituent, analkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10carbon atoms, a cyano group, and the like can be given. Theelectron-transporting compound is preferably one from which a thin filmcan be formed.

The following compounds can be given as specific examples of theelectron-transporting compound.

(Me is methyl and tbu is t-butyl.)

Furthermore, as materials used for the electron-injecting layer andelectron-transporting layer, the compounds represented by the followingformulas (E) to (J) may be used.

Nitrogen-containing heterocyclic derivatives shown by the formulas (E)and (F):

-   wherein Ar³¹¹ to Ar³¹³ are independently a nitrogen atom or a carbon    atom,

Ar³¹¹ is a substituted or unsubstituted aryl group having 6 to 60 ringcarbon atoms or a substituted or unsubstituted heteroaryl group having 3to 60 ring atoms, Ar^(311′) is an arylene group having 6 to 60 ringcarbon atoms or a substituted or unsubstituted heteroarylene grouphaving 3 to 60 ring atoms, and Ar³¹² is a hydrogen atom, a substitutedor unsubstituted aryl group having 6 to 60 ring carbon atoms, asubstituted or unsubstituted heteroaryl group having 3 to 60 ring atoms,a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,or a substituted or unsubstituted alkoxy group having 1 to 20 carbonatoms, provided that one of Ar³¹¹ and Ar³¹² is a substituted orunsubstituted fused ring group having 10 to 60 ring carbon atoms or asubstituted or unsubstituted monohetero fused ring group having 3 to 60ring atoms,

L³¹¹, L³¹² and L³¹³ are independently a single bond, a substituted orunsubstituted arylene group having 6 to 60 ring carbon atoms, asubstituted or unsubstituted heteroarylene group having 3 to 60 ringatoms, or a substituted or unsubstituted fluorenylene group,

R and R³¹¹ are independently a hydrogen atom, a substituted orunsubstituted aryl group having 6 to 60 ring carbon atoms, a substitutedor unsubstituted heteroaryl group having 3 to 60 ring atoms, asubstituted or unsubstituted alkyl group having 1 to 20 carbon atoms, ora substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,

n is an integer of 0 to 5, and

when n is two or more, plural Rs may be the same or different, andadjacent Rs may be bonded to each other to form a carbocyclic aliphaticring or a carbocyclic aromatic ring.HAr-L³¹⁴-Ar³²¹-Ar³²²  (G)Nitrogen-containing heterocyclic derivatives shown by the formula (G):

-   wherein HAr is a nitrogen-containing heterocyclic ring having 3 to    40 carbon atoms, which may have a substituent, L³¹⁴ is a single    bond, an arylene group having 6 to 60 carbon atoms, which may have a    substituent, an heteroarylene group having 3 to 60 atoms, which may    have a substituent, or a fluorenylene group which may have a    substituent, Ar³²¹ is a divalent aromatic hydrocarbon group having 6    to 60 carbon atoms, which may have a substituent, and Ar³²² is a an    aryl group having 6 to 60 carbon atoms, which may have a substituent    or a heteroaryl group having 3 to 60 atoms, which may have a    substituent.

Silacyclopentadiene derivatives shown by the formula (H) wherein X³⁰¹and Y³⁰¹ are independently a saturated or unsaturated hydrocarbon grouphaving 1 to 6 carbon atoms, an alkoxy group, an alkenyloxy group, analkynyloxy group, a hydroxyl group, a substituted or unsubstituted arylgroup, or a substituted or unsubstituted hetero ring, or X and Y arebonded to form a saturated or unsaturated ring, and R³⁰¹ to R³⁰⁴ areindependently hydrogen, halogen, an alkyl group, an alkoxy group, anaryloxy group, a perfluoroalkyl group, a perfluoroalkoxy group, an aminogroup, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonylgroup, an aryloxycarbonyl group, an azo group, an alkylcarbonyloxygroup, an arylcarbonyloxy group, an alkoxycarbonyloxy group, anaryloxycarbonyloxy group, a sulfinyl group, a sulfonyl group, a sulfanylgroup, a silyl group, a carbamoyl group, an aryl group, a heterocyclicgroup, an alkenyl group, an alkynyl group, a nitro group, a formylgroup, a nitroso group, a formyloxy group, an isocyano group, a cyanategroup, an isocyanate group, a thiocyanate group, an isothiocyanategroup, or a cyano group. These groups may be substituted and adjacentgroups may form a substituted or unsubstituted fused ring.

Borane derivatives shown by the formula (I) wherein R³²¹ to R³²⁸ andZ³²² are independently a hydrogen atom, a saturated or unsaturatedhydrocarbon group, an aromatic hydrocarbon group, a heterocyclic group,a substituted amino group, a substituted boryl group, an alkoxy group,or an aryloxy group, X³⁰², Y³⁰², and Z³²¹ are independently a saturatedor unsaturated hydrocarbon group, an aromatic hydrocarbon group, aheterocyclic group, a substituted amino group, an alkoxy group, or anaryloxy group, Z³²¹ and Z³²² may be bonded to form a fused ring, and nis an integer of 1 to 3, provided that when n or (3-n) is two or more,R³²¹ to R³²⁸, X³⁰², Y³⁰², Z³²² and Z³²¹ may be the same or different,provided that compounds where n is 1, X³⁰², Y³⁰², and R³²² are methylgroups, and R³²⁸ is a hydrogen atom or a substituted boryl group, andcompounds where n is 3 and Z³²¹ is a methyl group are excluded.

Gallium complexes shown by the formula (J) wherein Q³⁰¹ and Q³⁰² areindependently ligands represented by the following formula (K) and L³¹⁵is a halogen atom, a substituted or unsubstituted alkyl group, asubstituted or unsubstituted cycloalkyl group, a substituted orunsubstituted aryl group, a substituted or unsubstituted heterocyclicgroup, —OR(R is a hydrogen atom, a substituted or unsubstituted alkylgroup, a substituted or unsubstituted cycloalkyl group, a substituted orunsubstituted aryl group, or a substituted or unsubstituted heterocyclicgroup) or a ligand represented by —O—Ga-Q³⁰³(Q³⁰⁴) wherein Q³⁰³ and Q³⁰⁴are the same as Q³⁰¹ and Q³⁰².

wherein rings A³⁰¹ and A³⁰² are independently a 6-membered aryl ringstructure which may have a substituent and they are fused to each other.

The metal complexes have the strong nature of an n-type semiconductorand large ability of injecting electrons. Further, the energy generatedat the time of forming a complex is small so that a metal is thenstrongly bonded to ligands in the complex formed and the fluorescentquantum efficiency becomes large as the emitting material.

Specific examples of the substituents for the rings A³⁰¹ and A³⁰²forming the ligand of the formula (K) include halogen atoms such aschlorine, bromine, iodine, and fluorine, substituted or unsubstitutedalkyl groups such as a methyl group, ethyl group, propyl group, butylgroup, sec-butyl group, tert-butyl group, pentyl group, hexyl group,heptyl group, octyl group, stearyl group, and trichloromethyl group,substituted or unsubstituted aryl groups such as a phenyl group,naphthyl group, biphenyl group, anthranyl group, phenanthryl group,fluorenyl group, pyrenyl group, 3-methylphenyl group, 3-methoxyphenylgroup, 3-fluorophenyl group, 3-trichloromethylphenyl group,3-trifluoromethylphenyl group, and 3-nitrophenyl group, substituted orunsubstituted alkoxy groups such as a methoxy group, n-butoxy group,tert-butoxy group, trichloromethoxy group, trifluoroethoxy group,pentafluoropropoxy group, 2,2,3,3-tetrafluoropropoxy group,1,1,1,3,3,3-hexafluoro-2-propoxy group, and 6-(perfluoroethyl)hexyloxygroup, substituted or unsubstituted aryloxy groups such as a phenoxygroup, p-nitrophenoxy group, p-tert-butylphenoxy group, 3-fluorophenoxygroup, pentafluorophenyl group, and 3-trifluoromethylphenoxy group,substituted or unsubstituted alkylthio groups such as a methylthiogroup, ethylthio group, tert-butylthio group, hexylthio group, octylthiogroup, and trifluoromethylthio group, substituted or unsubstitutedarylthio groups such as a phenylthio group, p-nitrophenylthio group,p-tert-butylphenylthio group, 3-fluorophenylthio group,pentafluorophenylthio group, and 3-trifluoromethylphenylthio group, acyano group, a nitro group, an amino group, mono- or di-substitutedamino groups such as a methylamino group, diethylamino group, ethylaminogroup, diethylamino group, dipropylamino group, dibutylamino group, anddiphenylamino group, acylamino groups such as a bis(acetoxymethyl)aminogroup, bis(acetoxyethyl)amino group, bis(acetoxypropyl)amino group, andbis(acetoxybutyl)amino group, a hydroxyl group, a siloxy group, an acylgroup, substituted or unsubstituted carbamoyl groups such as a carbamoylgroup, methylcarbamoyl group, dimethylcarbamoyl group, ethylcarbamoylgroup, diethylcarbamoyl group, propylcarbamoyl group, butylcarbamoylgroup, and phenylcarbamoyl group, a carboxylic acid group, a sulfonicacid group, an imide group, cycloalkyl groups such as a cyclopentanegroup and cyclohexyl group, heterocyclic groups such as a pyridinylgroup, pyrazinyl group, pyrimidinyl group, pyridazinyl group, triazinylgroup, indolinyl group, quinolinyl group, acridinyl group, pyrrolidinylgroup, dioxanyl group, piperidinyl group, morpholidinyl group,piperazinyl group, carbazolyl group, furanyl group, thiophenyl group,oxazolyl group, oxadiazolyl group, benzoxazolyl group, thiazolyl group,thiadiazolyl group, benzothiazolyl group, triazolyl group, imidazolylgroup, and benzimidazolyl group. The above substituents may be bonded toform a further six-membered aryl ring or heterocyclic ring.

A preferred embodiment of the organic EL device is a device containing areducing dopant in an electron-transferring region or in an interfacialregion between a cathode and an organic layer. The reducing dopant isdefined as a substance which can reduce an electron-transferringcompound. Accordingly, various substances which have given reducingproperties can be used. For example, at least one substance can bepreferably used which is selected from the group consisting of alkalimetals, alkaline earth metals, rare earth metals, alkali metal oxides,alkali metal halides, alkaline earth metal oxides, alkaline earth metalhalides, rare earth metal oxides, rare earth metal halides, alkali metalcarbonates, alkaline earth metal carbonates, rare earth metalcarbonates, alkali metal organic complexes, alkaline earth metal organiccomplexes, and rare earth metal organic complexes.

More specific examples of the preferred reducing dopants include atleast one alkali metal selected from the group consisting of Na (workfunction: 2.36 eV), K (work function: 2.28 eV), Rb (work function: 2.16eV) and Cs (work function: 1.95 eV), and at least one alkaline earthmetal selected from the group consisting of Ca (work function: 2.9 eV),Sr (work function: 2.0 to 2.5 eV), and Ba (work function: 2.52 eV).Metals having a work function of 2.9 eV or less are particularlypreferred. Among these, a more preferable reducing dopant is at leastone alkali metal selected from the group consisting of K, Rb and Cs.Even more preferable is Rb or Cs. Most preferable is Cs. These alkalimetals are particularly high in reducing ability. Thus, the addition ofa relatively small amount thereof to an electron-injecting zone improvesthe luminance of the organic EL device and make the lifetime thereoflong. As a reducing agent having a work function of 2.9 eV or less,combinations of two or more alkali metals are preferable, particularlycombinations including Cs, such as Cs and Na, Cs and K, Cs and Rb, orCs, Na and K are preferable. The combination containing Cs makes itpossible to exhibit the reducing ability efficiently. The luminance ofthe organic EL device can be improved and the lifetime thereof can bemade long by the addition thereof to its electron-injecting zone.

An electron-injecting layer made of an insulator or a semiconductor mayfurther be provided between a cathode and an organic layer. By formingthe electron-injecting layer, a current leakage can be effectivelyprevented and electron-injecting properties can be improved. If theelectron-injecting layer is an insulating thin film, more uniformed thinfilm can be formed whereby pixel defects such as a dark spot aredecreased.

As the insulator, at least one metal compound selected from the groupconsisting of alkali metal calcogenides, alkaline earth metalcalcogenides, halides of alkali metals and halides of alkaline earthmetals can be preferably used. When the electron-injecting layer isformed of the alkali metal calcogenide or the like, the injection ofelectrons can be preferably further improved. Specifically preferablealkali metal calcogenides include Li₂O, K₂O, Na₂S, Na₂Se and Na₂O andpreferable alkaline earth metal calcogenides include CaO, BaO, SrO, BeO,BaS and CaSe. Preferable halides of alkali metals include LiF, NaF, KF,CsF, LiCl, KCl and NaCl. Preferable halides of alkaline earth metalsinclude fluorides such as CaF₂, BaF₂, SrF₂, MgF₂ and BeF₂ and the otherhalides corresponding to the fluorides.

Semiconductors forming an electron-injecting layer include one orcombinations of two or more of oxides, nitrides, and oxidized nitridescontaining at least one element of Ba, Ca, Sr, Yb, Al, Ga, In, Li, Na,Cd, Mg, Si, Ta, Sb and Zn. An inorganic compound forming anelectron-injecting layer is preferably a microcrystalline or amorphousinsulating thin film.

For the cathode, the following may be used: an electrode substance madeof a metal, an alloy or an electroconductive compound, or a mixturethereof which has a small work function (for example, 4 eV or less).Specific examples of the electrode substance include sodium,sodium-potassium alloy, magnesium, lithium, cesium, magnesium/silveralloy, aluminum/aluminum oxide, Al/Li₂O, Al/LiO, Al/LiF,aluminum/lithium alloy, indium, and rare earth metals.

The cathode is formed from these electrode materials by vapordeposition, sputtering or the like.

In the case where emission from the emitting layer is outcoupled throughthe cathode, it is preferred to make the transmittance of the cathode tothe emission larger than 10%. The sheet resistance of the cathode ispreferably several hundreds Ω/□ or less, and the film thickness thereofis usually from 10 nm to 1 μm, preferably from 50 to 200 nm.

Generally, in the organic EL device, pixel defects based on leakage or ashort circuit are easily generated since an electric field is applied tothe super thin film. In order to prevent this, it is preferred to insertan insulating thin layer between the pair of electrodes.

Examples of the material used in the insulating layer include aluminumoxide, lithium fluoride, lithium oxide, cesium fluoride, cesium oxide,magnesium oxide, magnesium fluoride, calcium oxide, calcium fluoride,aluminum nitride, titanium oxide, silicon oxide, germanium oxide,silicon nitride, boron nitride, molybdenum oxide, ruthenium oxide, andvanadium oxide. A mixture or laminate thereof may be used.

As for the method for fabricating the organic EL device, it can befabricated by forming necessary layers sequentially from the anode usingthe materials and the method as mentioned above, and finally forming thecathode. The organic EL device can be fabricated in the order reverse tothe above, i.e., the order from the cathode to the anode.

An example of the fabrication of the organic EL device will be describedbelow which has a structure wherein the following are successivelyformed on a transparent substrate: anode/hole-injecting layer/emittinglayer/electron-injecting layer/cathode.

At first, a thin film formed of an anode material is formed on atransparent substrate by vapor deposition or sputtering to form ananode.

Next, a hole-injecting layer is formed on this anode. As describedabove, the hole-injecting layer can be formed by vacuum deposition, spincoating, casting, LB technique, or some other method. Vacuum depositionis preferred since a homogenous film is easily obtained and pinholes arenot easily generated. In the case where the hole-injecting layer isformed by vacuum deposition, conditions for the deposition varydepending upon a compound used (a material for the hole-injectinglayer), a desired structure of the hole-injecting layer, and others. Ingeneral, the conditions are preferably selected from the following:deposition source temperature of 50 to 450° C., vacuum degree of 10⁻⁷ to10⁻³ Torr, vapor deposition rate of 0.01 to 50 nm/second, and substratetemperature of −50 to 300° C.

Next, an emitting layer is formed on the hole-injecting layer. Theemitting layer can also be formed by making a luminescent material intoa thin film by vacuum vapor deposition, sputtering, spin coating,casting or some other method. Vacuum vapor deposition is preferred sincea homogenous film is easily obtained and pinholes are not easilygenerated. In the case where the emitting layer is formed by vacuumvapor deposition, conditions for the deposition, which vary depending ona compound used, can be generally selected from conditions similar tothose for the hole-injecting layer.

Next, an electron-injecting layer is formed on the emitting layer. Likethe hole-injecting layer and the emitting layer, the layer is preferablyformed by vacuum vapor deposition because a homogenous film is required.Conditions for the deposition can be selected from conditions similar tothose for the hole-injecting layer and the emitting layer.

Lastly, a cathode is stacked thereon to obtain an organic EL device. Thecathode can be formed by vapor deposition or sputtering. However, vaporvacuum deposition is preferred in order to protect underlying organiclayers from being damaged when the cathode film is formed.

For the organic EL device fabrication described above, it is preferredthat the formation from the anode to the cathode is continuously carriedout, using only one vacuuming operation.

The method for forming each of the layers in the organic EL device isnot particularly limited. An organic thin film layer containing thecompound of the invention can be formed by a known method such as vacuumvapor deposition, molecular beam epitaxy (MBE), or an applying coatingmethod using a solution in which the compound is dissolved in a solvent,such as dipping, spin coating, casting, bar coating, or roll coating.

EXAMPLES

The invention will be explained in more detail with reference to thefollowing examples.

Synthesis Example 1

Benzo[g]chrysene was synthesized according to the following synthesisscheme.

(A-1) Synthesis of 9-(2-formylphenyl)phenanthrene

Under an argon atmosphere, 25.7 g of 9-bromophenanthrene, 16.5 g of2-formylphenylboronic acid and 2.31 g oftetraxis(triphenylphosphine)palladium(0) were placed in a flask. 340 mLof dimethoxyethane (DME) and 170 mL of a 2M aqueous sodium carbonatesolution were added to this flask, and the resultant was refluxed withstirring while heating for 8 hours. After cooling to room temperature,an aqueous phase was removed. An organic phase was washed with water andsaturated brine, and then dried with magnesium sulfate. After themagnesium sulfate was filtered out, the organic phase was concentrated.The residue was purified by means of silica gel column chromatography,whereby 25.0 g (yield: 89%) of intended 9-(2-formylphenyl)phenanthrenewas obtained.

(A-2) Synthesis of 9-[1-(2-methoxyvinyl)phenyl]phenanthrene

Under an argon atmosphere, 25.0 g of 9-(2-formylphenyl)phenanthrene,33.4 g of methoxymethyltriphenylphosphonium chloride and 300 mL oftetrahydrofuran (THF) were placed in a flask. During stirring at roomtemperature, 11.9 g of potassium t-butoxide was added to the flask.After further stirring at room temperature for 2 hours, 200 mL of waterwas added. The reaction solution was extracted with diethyl ether. Anaqueous phase was removed and an organic phase was washed with water andsaturated brine, and then dried with magnesium sulfate. After themagnesium sulfate was filtered out, the organic phase was concentrated.The resulting residue was purified by means of silica gel columnchromatography, whereby 24.0 g (yield: 87%) of intended9-[1-(2-methoxyvinyl)phenyl]phenanthrene was obtained.

(A-3) Synthesis of benzo[g]chrysene

24.0 g of 9-[1-(2-methoxyvinyl)phenyl]phenanthrene and 100 mL ofdichloromethane were placed in a flask. During stirring at roomtemperature, 6 drops of methanesulfonic acid were added to the flask bymeans of a Pasteur pipette. Stirring was conducted at room temperaturefor further 8 hours. After the completion of the reaction, 100 mL of a10% aqueous solution of potassium carbonate was added. An aqueous phasewas removed and an organic phase was washed with water and saturatedbrine, and then dried with magnesium sulfate. After the magnesiumsulfate was filtered out, the organic phase was concentrated. Theresidue was purified by means of silica gel column chromatography,whereby 5.21 g (yield: 25%) of intended benzo[g]chrysene was obtained.

Synthesis Example 2

Benzo[g]chrysene-10-boronic acid, which would be an intermediate of thecompound of the invention, was synthesized from the benzo[g]chrysene.

(B-1) Synthesis of 10-bromobenzo[g]chrysene

5.21 g of the benzo[g]chrysene and 50 mL of N,N-dimethylformamide wereplaced in a flask. 10 mL of a N,N-dimethylformamide solution of 4.00 gof N-bromosuccinimido was added. The resultant was heated with stirringat 80° C. for 8 hours. After cooling to room temperature, the reactionsolution was poured to 200 mL of water. Deposited solids were separatedby filtration, and washed with water and with methanol. The thusobtained solids were purified by means of silica gel columnchromatography, whereby 5.87 g (yield: 88%) of 10-bromobenzo[g]chrysenewas obtained.

(B-2) Synthesis of benzo[g]chrysene-10-boronic acid

Under an atmosphere of argon, 5.87 g of 10-bromobenzo[g]chrysene wasplaced in a flask. Then, 200 mL of dehydrated ether and 200 mL ofdehydrated toluene were added. After cooling the reaction solution to−40° C., 11 mL of a 1.6M hexane solution of n-butyl lithium was added,and the temperature was elevated to 0° C., followed by stirring for 1hour. After cooling the reaction solution to −60° C., 10 mL of adehydrated ether solution of 7.72 g of triisopropyl borate was addeddropwisely. The stirring was conducted for 5 hours while heating thereaction solution to room temperature. Then, 100 ml of an aqueous 10%hydrochloric solution was added, followed by stirring for 1 hour. Anaqueous phase was removed and an organic phase was washed with water andsaturated brine, and then dried with magnesium sulfate. After themagnesium sulfate was filtered out, the organic phase was concentrated.The resulting solids were washed with hexane, whereby 3.18 g (yield:60%) of intended benzo[g]chrysene-10-boronic acid was obtained.

[Synthesis of a Fused Aromatic Ring Derivative]

Example 1

The following compound 1 was synthesized by the following reaction.

Under an argon atmosphere, 7.72 g of the benzo[g]chrysene-10-boronicacid, 2.36 g of 1,4-dibromobenzene, 0.462 g oftetraxis(triphenylphosphine)palladium(0), 80 mL of toluene and 40 mL ofa 2M aqueous solution of sodium carbonate were placed in a flask. Theresultant was refluxed with stirring for 8 hours. After cooling to roomtemperature, the reaction solution was extracted with toluene. Anaqueous phase was removed, and an organic phase was washed with waterand then with saturated brine, and dried with magnesium sulfate. Afterthe magnesium sulfate was filtered out, the organic phase wasconcentrated. The residue was purified by a silica gel columnchromatography, whereby 5.04 g of white crystals were obtained. As aresult of mass spectrometry, the resulting crystals were confirmed to bean intended product. This intended product had an m/z value of 630 withrespect to a molecular weight of 630.23.

Example 2

The following compound 2 was synthesized by the following reaction.

A compound was synthesized in the same manner as in Example 1, exceptthat 4,4′-dibromobiphenyl was used instead of 1,4-dibromobenzene. As aresult of mass spectroscopy, the resulting compound was confirmed to bean intended product. This intended product had an m/z value of 706 withrespect to a molecular weight of 706.27.

Example 3

The following compound 3 was synthesized by the following reaction.

A compound was synthesized in the same manner as in the synthesis of thecompound 1, except that 2,7-dibromo-9,9-dimethylfluorene which had beenprepared by a known method was used instead of 1,4-dibromobenzene. As aresult of mass spectroscopy, the resulting compound was confirmed to bean intended product. This intended product had an m/z value of 746 withrespect to a molecular weight of 746.30.

Example 4

The following compound 4 was synthesized by the following reaction.

A compound was synthesized in the same manner as in the synthesis of thecompound 1, except that 1,4-dibromonaphthalene was used instead of1,4-dibromobenzene. As a result of mass spectroscopy, the resultingcompound was confirmed to be an intended product. This intended producthad an m/z value of 680 with respect to a molecular weight of 680.25.

Example 5

The following compound 5 was synthesized by the following reaction.

A compound was synthesized in the same manner as in the synthesis of thecompound 1, except that 2,6-dibromonaphthalene was used instead of1,4-dibromobenzene. As a result of mass spectroscopy, the resultingcompound was confirmed to be an intended product. This intended producthad an m/z value of 680 with respect to a molecular weight of 680.25.

Fabrication of Organic EL Device

Example 6

A glass substrate of 25 mm by 75 mm by 1.1 mm thick with an ITOtransparent electrode (anode) (GEOMATEC CO., LTD.) was subjected toultrasonic cleaning with isopropyl alcohol for 5 minutes, and cleanedwith ultraviolet rays and ozone for 30 minutes. The cleaned glasssubstrate having the transparent electrode lines was mounted in asubstrate holder of an apparatus for vacuum deposition. First, a 60nm-thick film of the following compound A-1 was formed on the surfacewhere the transparent electrode lines were formed so as to cover thetransparent electrodes. Subsequent to the formation of the A-1 film, a20 nm-thick film of the following compound A-2 was formed on this A-1film.

Further, the compound 1 of the invention and a styryl amine derivativeD-1 was deposited on this A-2 film in a thickness of 40 nm such that thefilm thickness ratio became 40:2. This film functioned as ablue-emitting layer.

The following compound (Alq) was deposited on this film to form a 20nm-thick film as an electron-transporting layer. The film serves as anelectron-injecting layer. Thereafter, LiF was formed into a film with athickness of 1 nm. On this LiF film, metal Al was deposited in athickness of 150 nm to form a metal cathode, whereby an organic ELdevice was fabricated.

Examples 7 to 10

Organic EL devices were fabricated in the same manner as in Example 6,except that the compounds 2-5 shown in Table 1 were used instead of thecompound 1.

Comparative Example 1

An organic EL device was fabricated in the same manner as in Example 6,except that the following compound B was used instead of the compound 1.

For the organic EL device fabricated in each Example above, the deviceperformance when driven at a current density of 10 mA/cm² and the halflife relative to the initial luminance of 1000 cd/m² were measured. Theresults are shown in Table 1.

Meanwhile, the luminous efficiency was measured by a method in which aprescribed voltage was applied to the device, and a current value atthat time was measured, and at the same time, an emission luminancevalue was measured by means of a luminance meter (CS-1000, aspectroradiometer manufactured by Konica Minolta Holdings, Inc.).

TABLE 1 Volt- Luminous Emis- age efficiency sion Life Host Dopant (V)(cd/A) color (hour) Example 6 Compound 1 D-1 6.5 6.5 Blue 6000 Example 7Compound 2 D-1 6.6 6.5 Blue 7000 Example 8 Compound 3 D-1 6.5 6.3 Blue5500 Example 9 Compound 4 D-1 6.7 6.7 Blue 8000 Example 10 Compound 5D-1 6.7 6.7 Blue 8000 Com. Ex. 1 Compound B D-1 7.0 6.0 Blue 4000

Example 11

A glass substrate of 25 mm by 75 mm by 1.1 mm thick with an ITOtransparent electrode (GEOMATEC CO., LTD.) was subjected to ultrasoniccleaning with isopropyl alcohol for 5 minutes, and cleaned withultraviolet rays and ozone for 30 minutes. The cleaned glass substratewith transparent electrode lines was mounted in a substrate holder of avacuum vapor deposition apparatus.

First, a 50 nm-thick film of4,4′-bis[N-(1-naphthyl)-N-phenenylamino]biphenyl (hereinafterabbreviated as the “NPD film”) was formed by resistance heatingdeposition on the surface where the transparent electrode lines wereformed so as to cover the transparent electrode. This NPD filmfunctioned as a hole-injecting/transporting layer.

Next, on the NPD film, the compound 1 was formed into a film of 40 nm byresistance heating deposition. Simultaneously, as the phosphorescentdopant, the following PQIr(acac) was deposited such that the contentthereof became 5 mass % of the entire emitted layer. This filmfunctioned as a phosphorescent emitting layer.

On this phosphorescent emitting layer, the following compound I wasformed into a film with a thickness of 10 nm by resistance heatingdeposition. The film of this compound I functioned as a hole-blockinglayer.

On this film, tris(8-quinolinol)aluminum (Alq₃) complex was formed intoa thickness of 30 nm. This film functioned as an electron-transportinglayer.

Then, Li as a reductive dopant (Li source: manufactured by SAES GettersCo., Ltd.) and Alq were co-deposited, whereby an Alq:Li film (filmthickness: 0.5 nm) was formed as an electron-injecting layer.

Metal aluminum was deposited on the Alq:Li film to form a metalliccathode (film thickness: 150 nm), whereby an organic EL device wasfabricated.

Examples 12 to 15

Organic EL devices were fabricated in the same manner as in Example 11,except that the compounds 2 to 5 shown in Table 2 were used instead ofthe compound 1.

Comparative Example 2

An organic EL device was fabricated in the same manner as in Example 11,except that the following compound C was used instead of the compound 1.

For the organic EL devices fabricated in Examples 11 to 15 andComparative Example 2, the device performance when driven at a currentdensity of 10 mA/cm² and the half life relative to the initial luminanceof 1000 cd/m² were measured. The results are shown in Table 2.

Meanwhile, EQE (external quantum efficiency) can be obtained from thenumber of photons which can be calculated from an emission spectrum andthe current density at the time of driving.

TABLE 2 Device performance Life Host Dopant EQE (%) (Hour) Example 11Compound1 PQIr(acac) 18.3 30000 Example 12 Compound 2 PQIr(acac) 18.430000 Example 13 Compound 3 PQIr(acac) 18.4 25000 Example 14 Compound 4PQIr(acac) 18.3 30000 Example 15 Compound 5 PQIr(acac) 18.3 30000 Com.Ex. 2 Compound C PQIr(acac) 18.2 3000

Example 16

The following compound 6 was synthesized by the following reaction.

A compound was synthesized in the same manner as in the synthesis of thecompound 1 (Example 1), except that N-phenyl-3,6-dibromocarbazole wasused instead of 1,4-dibromobenzene. As a result of mass spectroscopy,the resulting compound was confirmed to be an intended product. Thisintended product had an m/z value of 795 with respect to a molecularweight of 795.29.

Example 17

The following compound 7 was synthesized by the following reaction.

Under an argon atmosphere, 11.6 g of the benzo[g]chrysene-10-boronicacid, 2.36 g of 1,4-dibromobenzene, 0.693 g oftetraxis(triphenylphosphine)palladium(0), 120 mL of toluene and 60 mL ofa 2M aqueous solution of sodium carbonate were placed in a flask. Theresultant was refluxed with stirring for 8 hours. After cooling to roomtemperature, the reaction solution was extracted with toluene. Anaqueous phase was removed, and an organic phase was washed with waterand then with saturated brine, and dried with magnesium sulfate. Afterthe magnesium sulfate was filtered out, the organic phase wasconcentrated. The residue was purified by a silica gel columnchromatography, whereby 5.54 g of white crystals were obtained. As aresult of mass spectrometry, the resulting crystals were confirmed to bean intended product. The intended product had an m/z value of 906 withrespect to a molecular weight of 906.33.

Example 18

The following compound 8 was synthesized by the following reaction.

A compound was synthesized in the same manner as in the synthesis of thecompound 1 (Example 1), except that 1,8-dibromobenzofuran was usedinstead of 1,4-dibromobenzene. As a result of mass spectroscopy, theresulting compound was confirmed to be an intended product. Thisintended product had an m/z value of 720 with respect to a molecularweight of 720.25.

Examples 19 to 21

Organic EL devices were fabricated in the same manner as in Example 11,except that the compounds 6 to 8 which had been prepared in Examples 16to 18, which are shown in Table 3, were used instead of the compound 1.For the organic EL devices fabricated in Examples 19 to 21, the deviceperformance when driven at a current density of 10 mA/cm² and the halflife relative to the initial luminance of 1000 cd/m² were measured. Theresults are shown in Table 3.

Meanwhile, EQE (external quantum efficiency) can be obtained from thenumber of photons which can be calculated from an emission spectrum andthe current density at the time of driving.

TABLE 3 Device performance Life Host Dopant EQE (%) (Hour) Example 19Compound 6 PQIr(acac) 18.0 20000 Example 20 Compound 7 PQIr(acac) 18.225000 Example 21 Compound 8 PQIr(acac) 18.4 26000

Industrial Applicability

The fused aromatic ring derivative of the invention is preferable as amaterial for an organic EL device, in particular, as an emittingmaterial.

The organic EL device of the invention can be suitably used as a lightsource such as a planar emitting body and backlight of a display, adisplay part of a portable phone, a PDA, a car navigator, or aninstrument panel of an automobile, an illuminator, and the like.

The documents described in the specification are incorporated herein byreference in its entirety.

1. A fused aromatic ring derivative shown by the following formula (1):

wherein R_(a) and R_(b) are independently a hydrogen atom or asubstituent, m and n are independently an integer of 1 to 13, and when mand n are two or more, R_(a)s and R_(b)s may be independently the sameor different, and L₁ is a single bond or a substituted or unsubstituteddivalent linking group, provided that the fused aromatic ring derivativeshown by the formula (1) does not have an anthracene ring.
 2. The fusedaromatic ring derivative according to claim 1 shown by the followingformula (2):

wherein R_(a) and R_(b) are independently a hydrogen atom or asubstituent, m and n are independently an integer of 1 to 13, and when mand n are two or more, R_(a)s and R_(b)s may be independently the sameor different, and L₂ is a single bond or a substituted or unsubstituteddivalent linking group, provided that the fused aromatic ring derivativeshown in the formula (2) does not have an anthracene ring.
 3. The fusedaromatic ring derivative according to claim 1, wherein L₁ or L₂ is asubstituted or unsubstituted arylene group having 6 to 50 ring carbonatoms.
 4. A material for an organic electroluminescence devicecomprising the fused aromatic ring derivative according to claim
 1. 5.The material for an organic electroluminescence device according toclaim 4, which is an emitting material.
 6. An organicelectroluminescence device comprising: an anode, a cathode, and one ormore organic thin film layers comprising an emitting later between theanode and the cathode, wherein at least one of the organic thin filmlayers comprises the compound according to claim
 1. 7. The organicelectroluminescence device according to claim 6, wherein the emittinglayer comprises the fused aromatic ring derivative.
 8. The organicelectroluminescence device according to claim 7, wherein the emittinglayer comprises the fused aromatic ring derivative as a host material.9. The organic electroluminescence device according to claim 6, whereinthe emitting layer further comprises at least one of a fluorescentdopant and a phosphorescent dopant.
 10. The organic electroluminescencedevice according to claim 9, wherein the fluorescent dopent is anarylamine compound.
 11. The organic electroluminescence device accordingto claim 9, wherein the fluorescent dopant is a styrylamine compound.12. The organic electroluminescence device according to claim 9, whereinthe phosphorescent dopant is a metal complex compound.